They are really fun. Boca da Valeria is just a small village on a stream running into the Amazon. The ship anchors close by and you take tender rides. The Navigator actually landed us at the village to walk around it, but with more people on the Mariner, the tender rides past the village and also does a pink dolphin watch on the Amazon shore line. Natives from several villages come aboard the Mariner to sell their crafts, mostly carvings which are very unique. The villages aren't indiginous natives, but are Coblocos which is a mix of native, black, Portugese and whatever. At the other 3 villages you just walk around and enjoy the place.
Alter do Chau is a beach resort without any fancy hotels, but with a wonderful craft market and an enjoyable place to walk around.

Santorem is another walk around place and it is where about 100 Confederates settled in 1867 and failed at trying to grow cotton. Some of their buildings are still around.

Parintins is a larger city with more shops and restaurants. In the late afternoon wveryone is taken to a stadium where the Boi Bumba show is put on for the ships guests. It's a Carnival type show with very elaborate costumes and depicts the battle between the white and black bulls. It's a unique performance. Even the phone booths along the streets have a bull's head for a cover over them. They'll serve the Brazilian national drink as well (I can't remmeber the spelling) and be careful how many you drink.

The overnight in Manaus is one of the highlights of the cruise.

Just watching the scenery along the Amazon as we cruise by is very enjoyable.
Jim